package com.xzz.tree;

/**
 * @author: hhz
 * @create: 2021-12-17 12:24
 **/
public class Flatten {

    static class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;
        TreeNode() {
        }
        TreeNode(int val) {
            this.val = val;
        }
        TreeNode(int val, TreeNode left, TreeNode right) {
            this.val = val;
            this.left = left;
            this.right = right;
        }
    }

    public static void main(String[] args) {
        TreeNode node1 = new TreeNode(1);
        TreeNode node2 = new TreeNode(2);
        TreeNode node3 = new TreeNode(5);
        TreeNode node4 = new TreeNode(3);
        TreeNode node5 = new TreeNode(4);
        TreeNode node6 = new TreeNode(6);
        node1.left = node2;
        node1.right = node3;
        node2.left = node4;
        node2.right = node5;
        node3.right = node6;
        preTraverse(node1);
        System.out.println();
        flatten(node1);
        preTraverse(node1);
    }
    public static void flatten(TreeNode root) {
        if (null != root ){
            flatten(root.left);
            flatten(root.right);
            TreeNode left = root.left;
            TreeNode right = root.right;
            root.right = left;
            root.left = null;
            TreeNode temp = root;
            while(temp.right != null){
                temp = temp.right;
            }
            temp.right = right;
        }
    }
    public static void preTraverse(TreeNode node) {
        if (node != null) {
            System.out.print(node.val + " ");
            preTraverse(node.left);
            preTraverse(node.right);
        }
    }
}
